is there a way to adjust the vertical margins, i.e. left and right, on a single page / a certain region (the table of contents in my case) of a TeX document?

The reason why I'm asking is, that I've got a simple TeX-Article with two columns, therefor I set the margins left and right to somewhat around 2cm. However, I did not apply multicols on the table of contents (as I do not want that). Now the toc stretches over the full page width, which I find very ugly. Ideally it would have an individual width of 2/3 of the page, somewhat around 12cm.